This New Zealand native species of Mycena was observed to be bioluminescent by Anna Chinn in 2021 at the Fungal Foray in Stewart Island, New Zealand.
Unlike some Mycena species, only the stem of Mycena roseoflava is bioluminescent, not the whole fruiting body. Each mushroom is only about 1-2cm tall.
Armillaria novae-zealandiae, also known as harore in Maori or Honey Mushroom in English
This species of Armillaria, which is native to New Zealand and grows mainly on dead trees, has rarely been photographed at night. Like a number of other Armillaria species it is bioluminescent, emitting a very dim glow at night that is very elusive to both the human eye and a camera.
Interestingly it is the veil that glows the brightest.
A very long exposure time and high ISO settings are required to capture it on camera, and if you want to see it with your own eyes you need to wait at least 15-20 minutes in complete darkness for your eyes to become sensitive enough to see it.
These photos were taken at the 2021 Fungal Foray of the Fungal Network of New Zealand in Stewart Island.
Many thanks to Anna Chinn for leading a number of night walks to explore fungal bioluminescence! Also thanks to the following two researchers at Manaaki Whenua / Landcare Research: Jerry Cooper for species ID confirmation and Manpreet Dhami for finding this specimen of Armillaria novae-zelandiae, which has one mushroom with a closed veil and another with an open veil, uncovering the gills.